Technical Abstract:
Flame retardant behavior has been prepared by the layer-by layer assemblies of branched polyethylenimine (BPEI), kaolin, urea, diammonium phosphate (dibasic) on cotton fabrics. Three different kinds of cotton fabrics (print cloth, mercerized print cloth, and mercerized twill fabric) were prepared with solutions of mixture of BPEI, urea, diammonium phosphate (dibasic), and kaolin. Layer-by-layer assemblies for flame retardant properties were applied by the pad-dry-cure methods and each coating formula was rotated by 50 bilayers. It was to assay their effectiveness to resist flame propagation on treated fabrics of different constructions using the modified pill, 45° angle (ASTM D1230-01), and vertical flammability test (ASTM D6413-08) methods. In most of cases, char lengths of fabrics that passed the 45° angle and vertical flammability tests were less than 50% of original length and after-flame and after-glow times were less than one second. We tested the extent of char produced by untreated and treated fabrics at 600°C by thermogravimetric analysis and limiting oxygen indices (LOI, ASTM D2863-09). All untreated fabrics showed LOI values of about 18% oxygen in nitrogen. LOI values for the three types of treated fabrics were greater than 26% when add-on values for the formulation were 20.2, 18.2, and 19.5%. In addition to the treatment of the desired products their structural characterizations by FT-IR, CP/MAS 13C NMR, and SEM methods will be shown.